Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of bookseller Barnes & Noble (NYSE: BKS) got burned today, down by 24% at the low before closing off more than 16%, after the company reported a surprise loss in the second quarter.

So what: Revenue for the quarter came in at $1.9 billion, which generated a net loss of $0.17 per share. Both figures fell short, as the market was expecting $2 billion in sales and a profit of $0.03 per share.

Now what: B&N believes its full-year EBITDA will be on the low end of the previously announced guidance of $210 million to $250 million. After the quarter closed, the company released its Nook Tablet, which B&N says is now the fastest-selling Nook product, and the overall Nook business between all segments had revenue of $220 million. The digital segment,, continues to lose money while showing the most revenue gains as the company continues to invest in future growth.

Interested in more info on Barnes & Noble? Add it to your watchlist.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.